Basic Networking Explained: How To Connect Two Computers

How do you connect two computers to the Internet? That was a question that perplexed me the first time I tried to do it. I didn’t know what I needed to buy and how I would connect it all. Complicating the situation, there are several ways to connect two computers. One way we previously wrote a tutorial about was to connect two computers to one broadband modem. However this is not always possible for everyone and problems do occur.

We don’t want you to have the same problem I had, so here is everything you need to know to connect two computers to the Internet.

The Simplest Way To Connect Two Computers To The Internet

Almost everyone who buys high-speed Internet these days will receive a free router from their cable or DSL company. All you need is a way for your computer to talk to this router. You have two options:

Wireless can be used if your router is wireless and you have a wireless-enabled computer. You can tell your router has wireless support if it has one or more antennas. Most laptops made in the last 5 years have wireless too—to be sure, check your laptop’s specifications.

Wired (also called Ethernet) is most commonly used with desktop computers and older laptops. To use Ethernet, you need a special type of cord described below.

Connect Two Computers With Ethernet Cords

Ethernet is by far the most common method today for physically connecting two computer on the same network. There are three slightly different types of Ethernet cords available, which makes things slightly more complicated, but they’re all compatible with each other, so you don’t need to worry too much about buying the wrong cord.

All Ethernet cords end with an adapter that looks like a big U.S. telephone adapter. This adapter is called an RJ45 (U.S. telephone adapters are RJ11). At the end, it contains 8 parallel metal pins.

Most Ethernet cords are colored blue, although they can come in any color. Watch out for Ethernet cords colored yellow or red—these may be a special type of Ethernet called a crossover cable.

There are three different varieties of Ethernet cable. You can always tell which type of cable you have by reading the text printed on the cable. You have to look hard, as often the printing is in small, faint letters, but you should see something like the following text taken from an actual cable: “E111018 (A0l). Type CM 75°C 24AWG (UL) LL92833 CSA TYPE CMG 60°C SUN MICROSYSTEMS 180–1529–02 CATEGORY 5”.

Note the last part says, “CATEGORY 5”. It may also have said “CAT 5” or “CAT–5”, but it would mean the same thing. Also the CAT–5 designation can appear anywhere in the text, not just at the end. Besides CAT–5, there is also CAT–5E and CAT–6. Here are the differences between them:

CAT–5 was the fastest usable Ethernet cable for over a decade. But recently, faster routers have been able to use better cables to provider faster speeds to computers. If you’re just starting a home network, you’ll be fine using CAT–5 to connect two computers.

CAT–5E is used in the current fastest Ethernet routers—it’s about 10 times faster than regular CAT–5. The extra speed comes from building the CAT–5E cables to a more precise specification that reduces electromagnetic interference.

CAT–6 is also used in the current fastest Ethernet routers, but no current router can transmit fast enough to use all of the bandwidth available in CAT–6. Because of this, many companies use CAT–6 in their internal wiring so that they don’t need to rewire when faster routers come out.

When you go to buy Ethernet cords, it doesn’t matter which you buy unless you need the fastest speeds. If you have spare cash and you want to best performance, buy CAT–6. If you’re frugal and don’t do anything special on the Internet, buy CAT–5.

One thing you should always do is buy pre-made CAT–5 cords. Do this even if you’re an electrician familiar with making your own cords—Ethernet cords (especially CAT–6) are very hard to wire without damaging their electromagnetic shielding.

The Harder Way To Connect Two Computers

Sometimes your Internet Service Provider (ISP) doesn’t give you all of the equipment you need, so you need to go out and buy it yourself. Here’s exactly what you need to connect two computers together or to the Internet.

A Router will let two computers talk to each other. A router will also let those computers talk to computers on another network if one is available. Almost all routers today work on three networks: the Internet, a local wireless network, and a local wired network. You don’t need to use all three networks to use a router—just one network is fine.

Ethernet cables or Wireless cards depending on how you want to connect to your network. You need one cable or card for each computer, except for computers with built-in wireless cards.

A Modem if you want to connect to the Internet. There are dial-up phone modems, DSL modems, cable modems, and fiber optic (FIOS) modems; you also need an ISP that can communicate with your modem. It is also possible to connect two computers to one modem to share the internet connection.

Connect Two Computers Using A Switch

A switch is a special piece of networking equipment that looks like a router, but which is much simpler. A switch can connect two computers (or more), but it can only connect them on the same network. You can’t use a switch to connect two computers to the Internet unless you plug the switch into a router.

These days, switches are primarily used when you need to connect more computers together than you have ports on your router. For example, server rooms at big companies use switches with 96 ports on them to connect up to 95 computers to a router or another switch.

Although switches are dirt cheap, we suggest that you don’t buy one unless you’re sure you need it to connect two computers.

Connect Two Computers Directly

You can also connect two computers using a crossover cable without needing a router, a switch, or a modem. But configuring the computers to use the crossover cable is difficult for networking novices, so I suggest you look instead for a bridged USB cable (also called USB networking or USB-USB). Be careful buying a bridged cable—it should have a small box near the middle. If it doesn’t, don’t use it or it will burn out your computer.

After you get a bridged USB cable, plug it into both computers. Windows should automatically enable it for you. Then you can use the Link mode to copy files between the two computers.

About David

David A. Harding is a Linux Professional Institute certified system administrator and freelance writer with over 10 years experience working with Linux. He’s been published in over a dozen magazines and has given over 50 presentations about Linux–including two Software Freedom Day keynotes. Dave always loves to hear from readers and can be reached at dave@dtrt.org.